JP2767261B2 - catheter - Google Patents

Description

The present invention relates to a catheter.

[Conventional technology]

Catheters are generally used for blood vessels (especially
It is inserted into the fallopian tubes, ureters, and other various organs, and is used for the purpose of injecting or inhaling a liquid or ensuring the patency of a passage.

A common requirement for catheters is that the main body has a rigidity sufficient to transmit torque such as rotation.

This is because, when it is desired to change the direction of the distal end of the catheter at the insertion position of a blood vessel or an organ, when the base end of the catheter main body is rotated around the axis, the main body efficiently applies the rotational torque to the distal end. This is because it is more convenient to have a transmitting function.

In addition, the distal end portion continuous to the main body has not only the same rigidity as the main body in securing the ease of insertion at the time of insertion, but also has a desired direction and angle by rotating torque from the main body at the time of direction change. It is preferable to have a certain degree of flexibility to facilitate displacement.

[Problems to be solved by the invention]

The catheter as described above has a rigid main body,
The tip has rigidity and moderate flexibility.

The distal end of the catheter has various shapes (for example, a curved shape, a hook shape, or the like) so as to easily reach a target site according to an application region. As such a catheter, a catheter having a tip portion shaped so as to change its direction during insertion and enter the intended part direction is usually used.

However, the catheter whose distal end is deformed can easily change the direction, but on the contrary, the insertion operation other than the direction change becomes difficult due to the shape unique to the distal end. In order to solve this, an attempt has been made to forcibly return the tip to a straight line at the time of insertion, and then to insert the tip.However, the tip returns to its original deformed shape during insertion, and it is also difficult to insert It will be accompanied.

On the other hand, there is also a so-called all-purpose catheter which is linear from the beginning, but in such a catheter, the tip does not easily displace to a desired angle or direction at the time of a necessary change in direction, which causes inconvenience in the direction changing operation. .

Accordingly, it is an object of the present invention to provide a catheter having both ease of insertion and ease of turning.

[Means for solving the problem]

In order to achieve the above object, in the catheter of the present invention, at least the distal end has a rigidity such that the distal end can be easily inserted at the time of insertion, and is deformed and restored to a memory shape at body temperature ( Hereinafter, the organic polymer material is simply referred to as “shape memory material”), or both the tip and the body are made of the above-mentioned shape memory material, and the body has a torque transmitting property even in the human body. It is characterized by having a cooling water passage for holding it.

The catheter of the present invention is easy to insert into the human body because at least the distal end portion is made of the above shape memory material,
Once it reaches the direction change site, the distal end is deformed and restored to the shape stored in advance at the body temperature, and the direction change operation can be easily performed.

A catheter made of a shape memory material at both the distal end and the main body has exactly the same action as a catheter made of a shape memory material only at the distal end, but the entire catheter is made of a shape memory material, and only the main body has a torque transmission in the human body. Since it is preferable to maintain the fluidity, the main body has a cooling water passage for keeping the torque transmitting property even at the body temperature.

Regarding the torque transmission, it is preferable that the catheter having a distal end made of a shape memory material and the main body made of a material having such properties so as to maintain the torque transmission even at body temperature.

There is no particular limitation on the shape memory material used for at least the distal end portion or both the main body portion and the distal end portion as long as the object of the present invention can be achieved.
Examples such as (2) are exemplified.

(1) A mixture of a vulcanized rubber (A component), a polymer having no setting force near body temperature, and a (B component).

Is exemplified.

Natural rubber, butadiene rubber,
Synthetic rubbers such as styrene-butadiene rubber, isoprene rubber, butyl rubber, and acrylic rubber can be used.

As the component B, its melting point is around body temperature (preferably 32
Crystalline polymer which is polytrimethylene glutarate (melting point 39 ° C), polytrimethylene adipate (melting point 38 ° C), polytrimethylene pimerate (melting point 37 ° C), poly (octadecyl) Methacrylate)
(Melting point 34 ° C.), poly (hexadecyl acrylate) (melting point 33 ° C.) and the like.

The mixing ratio of the component A and the component B is usually 50 to 200 parts by weight with respect to 100 parts by weight of the former.

(2) A mixture of a thermoplastic elastomer (component (C)) and a component (B).

Examples of the component C include polystyrene (eg, a copolymer in which the hard segment is polystyrene and the soft segment is polybutadiene or polyisoprene),
Polybutadiene (eg, a copolymer in which the hard segment is syndiotactic 1,2-polybutadiene, a soft segment in which the soft segment is amorphous polybutadiene), a polyolefin-based (eg, a copolymer in which the hard segment is polypropylene and the soft segment is an ethylene-propylene rubber), Polyester type (eg, a hard segment is a polyester, a soft segment is a polyester copolymer), a polyamide type (eg, a soft segment is nylon 12, a soft segment is a polyether copolymer), a chlorinated polyethylene type (eg, a hard segment is Block type chlorinated polyethylene, copolymer in which the soft segment is random type chlorinated polyethylene), polyvinyl chloride (eg, the hard segment is polyvinyl chloride, and the soft segment is rubbery) Polymer), and the like.

The compounding ratio of the C component and the B component is usually 50 to 200 parts by weight of the latter with respect to 100 parts by weight of the former.

Further, there is no particular limitation on the material having torque transmitting properties even when heated by body temperature used for the main body, and a conventionally known material is sufficient. For example, polyimide, polyethylene, polyurethane, polytetrafluoroethylene,
Examples include ethylene tetrafluoroethylene and polyvinyl chloride.

In the case of manufacturing a catheter using the above-mentioned materials, it is performed as follows.

A catheter having both a tip portion and a body portion made of a shape memory material: A component (but not vulcanized) or a mixture of a C component and a B component is extruded and placed in a desired mold.
When the component is used, the rubber is vulcanized, molded into a desired large diameter in a deformed and restored state by means of heating or the like, and then cooled to a temperature equal to or lower than the melting point of the component B to store the shape. It is manufactured by making a predetermined small diameter by means such as stretching at a temperature not higher than the melting point of the component B.

A catheter made of a material having a tip portion made of a shape memory material and having a torque transmitting property even when the body portion is heated by body temperature: extruding the material of the tip portion to form the tip portion, and then forming the body portion material It is manufactured basically in the same manner as described above, except that it is manufactured by continuous extrusion so as to form the main body by extrusion.

〔Example〕

Hereinafter, the catheter of the present invention will be described based on examples.

In the embodiment of FIG. 1 (a), the catheter 1 has a distal end 3
Only the body portion 2 is made of a shape memory material, and the main body portion 2 is made of an organic polymer composition having a torque transmitting property even when heated by body temperature. FIG. 1 (b) shows a state where the catheter 1 of FIG. 1 (a) has been deformed and restored to shape memory at body temperature.

The catheter shown in FIG. 1A is, for example, an ethylene-propylene-diene terpolymer for a tip in a desired mold.
100 parts by weight, poly (octadecyl methacrylate) 100
Extrusion of a mixture of 2 parts by weight of dicumyl peroxide and 2 parts by weight of dicumyl peroxide, and then extruding polyethylene for the main body into a desired shape, vulcanizing the rubber component, and heating to form a large diameter in the desired deformed and restored state. After that, the shape is memorized by cooling to below the melting points of octadecyl and methacrylate.
Next, the octadecyl methacrylate is manufactured by stretching to a predetermined small diameter at a temperature equal to or lower than the melting point of methacrylate.

When the catheter 1 is inserted into a blood vessel, an organ, or the like, the distal end portion 3 is not sufficiently heated at body temperature and has the same rigidity as the main body portion 2. Easy to insert up to. When the body reaches the direction changing portion, the main body 2 still retains the torque transmitting property, but the tip 3 is sufficiently warmed at the body temperature (normally about 37 ° C.), and the angle stored in advance is stored. The distal end portion 3 can be easily changed in direction, and the catheter 1 can be easily inserted to the final insertion site.

The catheter 5 shown in FIGS. 2A and 2B is made of the same material as the distal end 3 of the catheter shown in FIG. 1 for both the main body 6 and the distal end 7. A cooling channel 8 is provided in the main body 6 in addition to the original flow path 9 in the catheter 5 as a treatment for maintaining the main body 6 in a low temperature state and maintaining torque transmission even in a human body. Have been. The catheter 5 has the same function and effect as the catheter 1, but circulates water into the main body 6 through the cooling water channel 8 during the insertion operation so that the temperature does not reach the temperature at which the main body 6 is restored to the memorized shape. Always cool.

〔The invention's effect〕

Since the catheter of the present invention is configured as described above, the following effects can be obtained.

At least the distal end or both the distal end and the main body are made of a shape memory material, that is, the above-mentioned organic polymer material having shape memory, so that not only the main body but also the distal end has the same rigidity as the main body at the time of insertion. However, when the tip reaches the turning point during insertion, the tip deforms and restores to the memorized state according to the body temperature, and the tip automatically performs a predetermined turning, so that the turning operation and the entire insertion operation can be easily performed. It can be carried out.

[Brief description of the drawings]

1 (a) and 1 (b) show one embodiment of the catheter of the present invention, wherein (a) is a partially omitted external view of a state before the deformation and restoration, and (b) is a deformation and restoration to a memory shape at body temperature. 2 (a) and 2 (b) show another aspect of the catheter of the present invention, and FIG.
(B) is a sectional view of the main body. 1, 5: catheter 2, 6: body 3, 7: tip 8: cooling water channel

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Yukio Morita 4-3 Ikejiri, Itami City, Hyogo Prefecture, Itami Works, Mitsubishi Electric Wire & Cable Co., Ltd. (56) References JP-A-62-155865 (JP, A) (58) ) Surveyed field (Int.Cl. ⁶ , DB name) A61M 25/00-29/04

Claims (3)

(57) [Claims] 1. A catheter characterized in that at least the distal end portion is made of an organic polymer material which has such rigidity that the distal end portion can be easily inserted at the time of insertion and deforms and restores to a memory shape at body temperature. 2. The catheter according to claim 1, wherein the main body is made of an organic polymer material having a torque transmitting property even when heated by body temperature. 3. When both the distal end portion and the main body are inserted, the distal end portion is made of an organic polymer material having such a rigidity that it can be easily inserted and deforming and restoring into a memory shape at body temperature. A catheter having a cooling water passage for maintaining torque transmission.